A Glaser magnet of improved field quality

A double pole-gap design for low spherical aberration in thin solenoids

“…We verified this for the long solenoid of R/L¼ 0.11, L/R¼ 9.1 (L ¼256 mm, R ¼28 mm) from Ref. [7] mentioned above. Hence for very long solenoids, the two slot design is unpractical, though it is better than a single slot design.…”

“…We also find that the full open slot design has lowest aberration for long solenoids with R=L o 0:46. It was mentioned above that the tapered slot design has higher spherical aberration than the full open air slot design [7]. Similarly the spherical aberration in Ref.…”

“…There are a few designs reported in literature that reduce the spherical aberration in shielded solenoids for ion focusing, with a pole gap (air-slot), by choosing very small slot size or by tapering the slot [6,7]. But long solenoids have lowest spherical aberration when they have a full open air-slot at aperture, e.g., the spherical aberration in Ref.…”

A variational calculus approach for improving the field quality in Glaser magnets

“…We do this by shaping the pole pieces. In our earlier works [11,12] we showed that the spherical aberration can be decreased by tapering the pole pieces outwards. Here we have further modified the pole pieces to obtain better results.…”

“…Spherical aberration, however, is quite large in this magnet, and one endeavours to reduce it. Recently we worked on a scheme for improving the field quality and reducing the spherical aberration of Glaser magnets by shaping the profile of the pole pieces [11,12]. We showed that one can reduce the spherical aberration (keeping the focal power fixed) by tapering the pole pieces outwards.…”